P2Y receptors are a family of purinergic receptors, G protein-coupled receptors stimulated by nucleotides such as ATP, ADP, UTP, UDP and UDP-glucose. To date, 12 P2Y receptors have been cloned in humans (Abbracchio MP et al, 2006; Fischer W and Krugel U, 2007). P2Y receptors are present in almost all human tissues where they exert various biological functions based on their G-protein coupling. Purine nucleotides are involved in a large number of intermediate metabolic pathways, taking part as substrates, products or allosteric factors.